Process for treating hydrocarbon oils



May 17, 1932. s. H. DIGGs ET AL PROCESS FOR TREATING HYDROCARBON ILS-iled ual-,cn 5, 1928 Patented May 17, 1932 PATEN'I OFFICE UNITED STATESSTERLING- H. DIGGS AND JOHN M'. MCGEE, OF CASPER, WYOMING, AND THOMAS S.COOKE,

F NEW YORK, N. Y., ASSGNORS TO STANDARD OIL "COMPANY, OF WRITING, IN-

DIANA, A CORPORATION 0F INDIANA PROCESS FOR TREATING HYDROCARBON OILSApplication led March 5, 1928. Serial No. 259,314.

' The present invention relates to improvements in the art of treatingsulfur containing oils, and will be fully understood from the followingdescription, illustrated by the l accompanying drawing, in whichapparatus suitable for carrying the invention 1nto effect isdiagrammatically illustrated.

Referring to the drawing, the numeral 5 indicates a still setting inwhich is mounted the still 6, illustrated as of the shell or horizontalcylindrical type. Still 6 is provided with feed line 7 and draw-off line8. From the still, a. vapor line 9 leads to the lower portion of abubble tower 10, which is provided with a cooling oil inlet line 11 anddraw-off line 12. A vapor line 13 leads from the bubble tower 10 to acondenser 14 from which the condensate passes into the receiver 15. Fromthe receiver 15 the distillate passes, or, preferably, is forced by pump16, through line 17, which is provided with a valve 18, into an` oriceplate mixer 19. The orifice plate mixer 19 is preferably of the singlehole (knot-hole mixer) type and is provided with line 20 through whichsulfuric acid may be introduced into the mixer.

The distillate and acid from the mixer 19 pass through line 21 intotreating tank 22, which is provided with a valved draw-ofi' line 23. Anysuitable means for cooling the treated distillate, the temperature ofwhich is raised by the heat of reaction, in treating tank 22 may beemployed. In the illustration given, a coiled pipe 24 is shown throughwhich a cooling iuid may be passed to maintain the materilal undertreatment at the deside temperature. Treated oil is withdrawn from tank22 through the 'valved line 25 and preferably is forced by pump 26through line 27 into the still 28. Still 28 is preferably a steam still,suitably lagged and mounted on still setting 29. It is provided with asteam line 30 and a draw-off line 31. Vapor line 32 leads from still 28to a point near the bottom of bubble tower 33, which is equipped with acooling oil line 34 and a draw-off line 35. From the bubble tower 33 avapor line 36 leads-to condenser 37 from which condensate passes throughline 38 into 'receiver 39. The receiver 39 is provided with a valveddraw-oli line 40.

In the operation of the process, any suitable charging stock may beAintroduced into still 6 through line 7. A crude oil or any otherheavyoil may, if desired, be used. We prefer, however, to yuse as a chargingstock a raw distillate, such as, for example, is obtained from apressure still. By means of the bubble tower 10, the vapors passing fromstill 6 through the bubble tower 10 are so controlled as to producein'receiver 15 a crude gasoline with an end point preferably not lessthan 5 F. and not more than 35 F. higher than that desired for thefinished product. This first distillation in practice has been found toeliminate, as bottoms, approximately 40% of the pressure stilldistillate which it is unnecessary to treat and which may be withdrawnfrom the still through line 8. It is to be understood that insteadof-distilling a pressure still distillate in still 6 in order to obtainthe desired crude gasoline product, this product may be obtaineddirectly from still 6 when pressure still charging stock is crackedtherein or when any heavy oil, such as crude oil, is distilled therein.

The crude gasoline from receiver 15 is passed through the orifice platemixer 19, where it is mixed with the acid introduced into the mixerthrough line 20. While acid of any suitable strength may be used, it ispreferred to use 98% sulfuric acid. The amount used must, ofcourse,depend upon the sulfur content of the cru-de gasoline and the.

allowable total sulfur in the finished product. By way ofexample, for agasoline containing .400 to .450% of sulfur, 25 lbs. of 98% acid per 50gallons has been found to give a finished product of 0.09 sulfur.Although the mixing may be carried on by agitation with air, or othermeans, it is preferred to use an orifice plate mixer. From the mixer 19the oil and acid pass into the treating tank 22 in which the treatingaction takes place, resulting in the polymerization or other changes ofthe sulfur compounds which will, subsequently, be left in the bottomsupon redistillation. Heavy material, such 'as sludges, when de- Duringthe treating operation it is preferred to keep thetemperature of the oilcomparatively low, say below 100 F. It has` been found that treatment oflower temperatures improves the color fand decreases the formation ofalkyl sulfuric acids, esters and oxidation products. For this purpose,the oil in tank 22 may be circulated through cooling brine or, asillustrated in the drawing, a cooling fluid may be passed through coilsarranged within tank 22.

The treated oil in tank 22 is withdrawn through line 25 and may beforced by pump 26 through line 27 into still 28. While the polymerizedor changed sulfur compounds may be removed by alkali treatment, or otherknown methods from the crude gasoline, we prefer to redistill the crudegasoline with steam at temperatures preferably below 300 F. It has beenfound that when the crude gasolinewas redistilled with ire alone to atemperature of 500 F., a considerable amount of S'O2 was evolved with anaccompanying formation of black tarry materials in the bottoms. Byredistilling with steam and tliuskeeping the temperature of the bottomsbelow 300 F., a distillate of better color, has been secured without theevolution of any substantial amount of SO2. Steam is introduced into thestill through pipe 30, the vapors generated passing through line 32 intobubble tower 33 where a portion of the vapors' are condensed. Thedesired lighter fractions pass out of the bubble tower into vapor line36 and are condensed in condenser 37. A condensate, having the desiredend point, is recovered in receiver 39. v' Ihe treatedV gasoline may besweetened, either before or after theredistillation. Bottoms in still28, containing polymerized or changed sulfur compounds, may be withdrawnthrough draw-off line 31.

While the process is particularly adapted for treating light distillatessuch as crude gasoline, it is clearly applicable for the treatment `ofother oils.

It is to be understood that the specific detailsof apparatus and methodhereinbefore set vforthare for the purpose of illustration 'and 'are notintended to be regarded as limitations upon thescope of the claims,except .V5-6 "as contained in the following claims.

. We claim:

1. The method of treating sulfur contain- *vf-ing vhydrocarbon oilscomprising distilling said oils to form a distillate having an endpointl not less 'than 5 F. nor more than 35 F. above vthat of the.desired inished product, treating saiddistillate with sulfuric acid,and redistilling'said.treated distillate to form a 'distillate producthaving` theend point de- A s. y A. G5

ired.

22.- AThe method of treating sulfur containv prevent the formation inghydrocarbon oils omprising distilling said oils to produce a dtillatehaving an end point not less than 5 F. nor more than 35 F. above that ofthe desired inished product, treating said distillate with sulfuricacid, and redistilling said distillate at temperatures below about 300F. to form a distillate product having the end point desired.

3. The method of treating sulfur containling hydrocarbon oils comprisingdistilling said oils to form a distillate having an end point not lessthan 5 F. nor more than 35 F. above that of the desired finishedproduct, treating said distillate with sulfuric acid, redistilling withsteam said treated distillate at'temperatures below 300 F. to produce adistillate having the end `oint desired.

4f.y The method of treating sulfur containing hydrocarbon oilscomprising distilling a sulfur containing oil to produce a distillatehaving an end point not less than 5 nor more than 35 F. above that ofthe'desired nished product', treating a distillate product of saiddistillation with sulfuric acidto polynierize the sulfur compoundstherein, maintaining the temperature of said distillate while undergoingtreatment suliiciently low to prevent the formation of substantialamounts of alkyl sulfuric acids, esters and oxidation products, andsubsequentlyredistilling said distillate to free the major portion of itfrom said acid and sulfur compounds. A

5. The method of treating sulfur containing hydrocarbon oils comprisingdistilling -said oils to produce a distillate having an en point notless than 5 nor more than 35 above that of the desired finished product,condensing the generated vapors, treating the condensate with sulfuricacid to polymerize the sulfur compounds therein, while main- .tainingthe temperature of said distillate below about 100 F., and subsequentlydistilling said condensate to free the maior portion of it from saidacid and sulfur compounds.

6. The method of treating sulfur containing hydrocarbon oils comprising.distilling said oils to produce a distillate having an end point notless than 5 nor more than 35 l* above that of the desired finishedproduct, condensing the generated vapors, treating the condensate withsulfuric acid to polymerize the sulfur compounds therein, therebyraising the temperature of said distillate, cooling said distillatewhile undergoing treatment to of undesirable compounds therein, andsubsequently distilling said condensate to free the maJor portion of itfrom said acid and polyinerized sulfur comounds.

7. The method of treating sulfur containing hydrocarbon roils comprisingdistilling said oils to produce a ldistillate having an end condensingthe generated vapors, treating the condensate with 98% sulfuric acid topolymerize the sulfur compounds therein, thereby raising the temperatureof said distillate, 5 cooling said distillate while undergoing treatmentto prevent the formation of undesirable compounds therein, andsubsequently distilling said condensate to free the major portion of itfrom said acid and polymerized sulfur' 0 compounds.

8. The method of treating sulfur containing hydrocarbon oils comprisingdistilling said oils to produce a distillate having an end point notless than 5 F. nor more than 35o F. above that of the desired finishedproduct, treating said distillate with 98% sulfuric acid,redistillingsaid treated distillate to form a distllate product havingthe endpoint desire 9. The method of treating sulfur containinghydrocarbon oils comprising distilling y said oils to produce adistillate having an end point not less than 5 F. nor more than 35 F.above that of the desired finished product, treating` said distillatewith sulfuric acid, maintaining the temperature of the distillate whileundergoing treatment sufficiently low to prevent the formation ofundesirable compounds,` and redistilling said distillate to form adistillate product having the end point desired.

10. The method of treating sulfur containing hydrocarbon oils comprisingdistilling said oils to produce a distillate having an end point notless than 5 F. nor more than 35 F.

above that of the desired finished product, treatingl said distillatewith sulfuric acid, maintaining the temperature of the distillate whileundergoing treatment below about 100 F., and redistilling saiddistillate to form a distillate product having the end point desired. Y

ll. The method of treating sulfur containing hydrocarbon oils comprisingdistillingsaid oils to produce a distillate having an end point not lessthan 5 F. nor more than 35 F. above that of the desired finishedproduct, treating said distillate to polymer'rae the sulfur compoundstherein, redistilling said@ reated distillate to form distillateproducts ihavmg the end point desired, and withdrawing said polymerized.sulfur compounds. 12. The Amethod of treating sulfurcontaininghydrocarbon oils comprising distilling '1 said oils, condensing thegenerated vapors thereof to form a distillate having an end point notless than 5 F. nor more than 35 F. above that of the desired finishedproduct, mixing said distillate with sulfuric acid. 0 maintaining a poolof. condensate and acid so admixed, cooling saidpool of the dis illatcIand acid, and subsequently redistilling said treated.VV distillate toproduce la. distillate of the desired end point.

5 13. The method of treating light hydrocart bon distillates comprisingdistilling said oils,

condensing the generated vapors thereof to form a distillate having anend point not less than 5 F. nor more than 35 F. above that of thedesired finished product, mixing said distillate with sulfuric acid, andredistilling ing light hydrocarbon distillates comprising distillingsaid distillates to produce a distillate product having an end point notless than 5 F. nor more than 35 F. above that of the desired finishedproduct, treating said second-mentioned distillate with sulfuric acid,maintaining the temperature of said second-mentioned distillate below100 F. while underging treatment, and redistilling said second-mentioneddistillate to form a distillate product of the end point desired.

15. The method of treating sulfur containing hydrocarbon oils comprisingdistilling said oils to produce a fraction having the end-point of thedesired distillateproduct and also mixed therewith a fraction having anend point not less than 5 F. nor more than 35 F. above the end-point ofsaid first mentioned fraction, treating said mixed distillates withsulfuric acid to polymerize the sulfur compounds therein, distillinglsaid treated distillates to produce a distillate of the desiredend-point, andremoving polymerized sulfur compounds in said secondmentioned fraction as residue from said second distillation.

16. The method of treating sulfur containing hydrocarbon oils comprisingdistilling saidroils to produe a fraction having the end-pointer thedesired distillate product and also mixed therewith a fraction having anend point not less than 5 F. nor more than 35 F. above the end-point ofsaid first mentioned fraction, treating said mixed fractions withsulfuric acid to polymerize the sulfur compounds therein, maintainingthe temperature of the fractions whileundergoy. ing treatmentsufficiently low to prevent the formation of undesirable compounds,distilling said treated fractions to produce a dis-A tillate ofthedesired end-point, and removing polymerized sulfur compounds in saidsecond mentioned fraction as residue from said second distillation.

ln testimony whereof, we have hereunto sct our hands this 14th day ofFebruary, 1928, and 20th day of February, 1928.

STERLING H. DIGGS. JOHN M. MCGEE. THOMAS S. COOKE.

summum: oF coRnEcTloN.

Patent Ito-1,858,394. May 17, 1932,

STERLING n, orcos ET AL.

It. is hereby certified Athat error appears in the` printedspecification of the 'above numbered patent requiring correctionasfoliows: Page 2, line 6, ior the word "oi" reati at: page 3, lines 96and 98, claim 15, for "distiliates" read fractions; and that the saidLetters Patent should be reati with these corrections therein that thesame may conform to the record of the case in the Patent Oiioe,

Signed and seaie. this 12th @ay oi hiy, A. it-932.

M. L Moore, p (Seei) Acting- Commissioner of Patents-

